The Punjab government on Tuesday extended the suspension of mobile internet and SMS services in Tarn Taran, Ferozepur, Moga, Sangrur and Amritsar's Ajnala sub-division and a few areas in Mohali till Thursday noon.

The curbs will be lifted from the rest of the state from Tuesday noon, the department of home affairs and justice said in an order.

The curbs on mobile internet and SMS services were imposed by the Punjab government on Saturday as the state's police force launched a major crackdown against radical preacher Amritpal Singh and members of his outfit 'Waris Punjab De'.

"All mobile internet services, all SMS services and all dongle services... shall continue to remain suspended from March 21 (12.00 hours) to March 23 (12.00 hours) only in the districts Tarn Taran, Ferozepur, Moga, Sangrur, sub-division Ajnala in Amritsar, areas adjoining YPS chowk and airport road, both in SAS Nagar," the order said.

This is being done to "prevent any incitement to violence and to prevent any disturbance of peace and public order", it added.

The order clarified that mobile internet services in all the remaining areas of the state should start functioning normally from 12 noon on March 21.

The Punjab Police on Monday flagged a possible "ISI angle" as it invoked the stringent National Security Act against five men linked to the radical preacher, whose uncle and driver surrendered amid the state-wide crackdown.

Punjab Inspector General of Police (Headquarters) Sukhchain Singh Gill told reporters that specialised units are involved in the efforts to nab the preacher – who gave police the slip during a car chase in Jalandhar district on Saturday.

The Khalistan sympathiser's uncle Harjit Singh and driver Harpreet Singh gave themselves up before police past Sunday midnight.

Harjit Singh, who officials say helped his nephew gain control over the accounts of "Waris Punjab De", is among the five slapped with the NSA, which allows the preventive detention of anyone who could threaten national security or public order.

Harjit Singh was shifted to the central jail in Assam's Dibrugarh, where the other four were brought on Sunday. They are Daljit Singh Kalsi, Bhagwant Singh, Gurmeet Singh and 'Pradhanmantri' Bajeka.

Gill has indicated that the preacher could also be detained under the NSA.

The Punjab Police operation began Saturday, weeks after Amritpal Singh and his supporters stormed the Ajnala police station near Amritsar to secure the release of an arrested associate.

The episode had raised fears over the possibility of the return of Khalistani militancy to the border state.

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